Lint-free medical applicator



United States Patent Office 3,376,867 LINT-FREE MEDICAL APPLICATORMaurice S. Kanbar, 105 E. 15th St. 10003, and Raymond David Sudarsky,422 E. 58th St. 10019, both of New York, N.Y.

Filed Nov. 25, 1964, Ser. No. 413,928 10 Claims. (Cl. 128269) Thisinvention relates generally to absorbent medical pads, sponges, tampons,dressings and the like, and more particularly to a lint-free swab formedof texturized synthetic material.

Swabs are widely used as medical applicators and for various delicatecleaning operations. Conventional swabs are fabricated from a small massof natural fibers, such as cotton, wool or gauze, and are commonly usedin medical practice for mopping up blood duringan operation ordischarges, or for applying antiseptics to the body.

While swabs made of such fibrous materials as cotton are highlyabsorbent, even though the material is sterile, it may nevertheless beunsuitable for certain uses. Thus in surgical situations and in othercases requiring the total absence of foreign matter, the usual swab isnot acceptable because of lint. Short lengths of the material and minuteparticles of lint are present even in the most carefully prepared swab,and the dustlike particles tend to precipitate onto the surface beingswabbed. Thus when an incision is made and then swabbed, lint may beleft behind in the incision and sealed therein after the incision issutured. This foreign matter may interfere with the healing process andgive rise to medical difiiculties.

Accordingly, it is the primary object of the present invention toprovide a swab or other absorbent medical applicator formed of a highlyadsorbent, lint-free material. Though the invention will be describedmainly in connection with the fabrication of a swab, it is to beunderstood that the same materials and methods are equally applicable tothe making of medical sponges, tampons, bandages, dressings and a widevariety of absorbent bodies required in medical and surgical situationsin which freedom from lint is a vital desideratum.

More specifically, it is an object of the invention to provide a swabformed of long texturized synthetic continuous filaments rather thanshort fibers of natural material. While such synthetic filaments, whenunmodified,

ordinarily have low adsorption characteristics, they are rendered highlyadsorbent by a false-twist or other texturizing technique.

A significant feature of the invention resides in the fact that theabsorbent material is radiologically opaque, hence in the event thesponge, swab or pad is inadvertently left within the patients bodyduring surgery, its presence and location can be determined by X-raytechniques.

Also an object of the invention is to provide a sterile, highlyadsorbent medical applicator or sponge which may be manufactured andsold at relatively low cost, and which is particularly useful as anapplicator or for cleansing purposes in those situations, as in eyeoperations, where even the most minute residue from the swab is highlydeleterious.

Briefly stated, these objects are accomplished by texturizing individualmulti-filament yarns of synthetic material to form a bulked yarn, aplurality of bulked yarns being clustered to form a tow which is woundabout an applicator stick to form a swab of high quality. The resultantswab is not composed of short fibers of natural material but of aplurality of continuous filaments each one of which is relatively longand cannot separate from the mass of the swab. Basically the sametechnique can be used to form dressings, tampons and a variety of othermedical applicators or sponges.

3,376,867 Patented Apr. 9, 1968 For a better understanding of theinvention, as well as other objects and further features thereof,reference is made to the following detailed description to be read inconjunction with the accompanying drawing, wherein:

FIG. 1 shows schematically a system for producing a tow of adsorbentyarns in accordance with the invention;

FIG. 2A is an enlarged view of unmodified yarn;

FIG. 2B is a micrograph of one false-twisted yarn made by the system;and

FIG. 3 is a swab made from the tow material.

The present invention makes use of synthetic materials such aspolyamide, vinyl, polyester or acrylic yarns, formed of fine continuousfilaments. The adsorption characteristics of continuous filament yarnsis relatively low as compared to yarns of natural materials, such ascotton or wool. Adsorption is a process by which the surface of a solid(the adsorbent) attracts and holds any atom or molecule (the adsorbate)from .a solution with which it is in contact. The total amount of liquidadsorbed depends on the hy-drophilic aifinity between the adsorbent andthe adsorbate, and the total surface exposed to the mobile particles.Finely divided yarn materials have high adsorbent capacities because ofthe enormous amount of exposed surface area relative to their mass.

Continuous-filament yarns have a low adsorption characteristic but canbe rendered highly adsorbent by a process known as texturizing orbulking. Bulked or textured yarns are those which have been treated soas to have greater apparent bulk or volume than their yarn numbersindicate they should. The texturizing process acts to introduce crimps,coils, loops or crinkles into otherwise smooth, continuous filaments,and in the case of nylon or other thermoplastic materials, it exploitsthe thermoplasticity of the material and its ability to be deformed,heatset and developed.

While the present invention is not limited to nylon, we shall forpurposes of describing the technique, make use of this material as anexample of how the invention is carried out. Essentially, the inventiontakes individual yarns of nylon composed of a multiplicity of fine,smooth and continuous filaments and texturizes the yarn to form a bulkedyarn in which the individual filaments thereof are crimped or otherwisebulked.

A large number of such bulked yarns is then brought together into a tow,and because of their bulked characteristics, the several yarnsintertangle to form a fiufiy and highly adsorbent matting. In accordancewith Well-known swab-making techniques, the tow is then twisted about astick to form individual adsorbent tips. Alternatively, the tow may bewound about a removable mandrel to form a ball, which ball serves as aswab or sponge. The resultant ball or pad may be incorporated within awoven or knitted sheath which is shaped to provide a dressing having adesired configuration.

Preferably, the texturizing of the continuous-filament nylon yarn iscarried out by the so-called false-twist process which sequentiallycarries out twisting, heat-setting and untwisting, thereby providing acontinuous operation. The yarn 10, as shown in FIG. 1, is amulti-filament nylon taken from a yarn package 11 and is fed by feedrolls 12 at a controlled tension which is determined by a suitabletensioner 13, through a heating zone 14. From the heating zone, theheat-softened yarn passes into a false-twist spindle 15, the yarn beingdrawn therefrom by a delivery roll 16. The twist between the false-twistspindle and the feed rolls is set into the yarn by heating and coolingbefore it passes through the false-twist spindle.

The principle of operation is as follows: If a stationary multi-filamentyarn is held at both ends and twisted in the center by a hollowfalse-twist spindle, then equal amounts of twist with opposingdirections of spirality will be imparted on each side of the spindle.While each half of the yarn, if considered separately, appears to have areal twist therein, the algebraic sum of twist of the yarn through thelength thereof as a whole is zero. With the false-twist spindle rotatingcontinuously but with the yarn passing forward, the system reaches astate of equilibrium wherein no twist exists after the yarn has passedthrough the tube. This happens because of the cancelling out of thetwist on the delivery side of the tube Thus when equilibrium is reached,there are constantly twisted filaments on the intake side of therotating spindle, and untwisted filaments on the output side thereof.Since the heater is on the input side of the spindle, with enough spaceleft for cooling between the twisted yarn passing through the rotatingspindle, the three basic steps of twisting, heat-setting and untwistingare carried out simultaneously.

In FIG. 2A there is shown in enlarged view an unmodified multi-filamentyarn formed of continuous nylon filaments 10a, 10b, 100, etc., such as70-denier, 34-filament yarn. When this yarn is false-twisted, theresultant structure, as shown in the micrograph in FIG. 2, is composedof individual filaments which are looped, curled, twisted, tangled orotherwise distorted to form a bulked yarn of relatively high volume.False-twist yarns of this type have very high water intake as comparedto continuous-filament yarns not so textured.

Thus continuous-filament yarns having a denier of 2 per filament have awater adsorption of 355%, whereas the same yarn when false-twisted has awater adsorption of 1,65l%. Edge-crimped yarn, on the other hand, of 2denier per filament, has a water adsorption of 906%, whileair-texturized yarn has a water adsorption of 558%. It is to be noted,therefore, that the false-twist technique produces a higher percentageof adsorption than other texturizing methods.

The bulked yarns from a battery of identical false-twist systems arebrought together in a tow 17 and because of the looped and curled natureof the yarns, the yarns intertangle and interlock to form a matted masswhose appearance is similar to commercially produced adsorbent cotton.This tow is then wound about a stick 18 to form an adsorbent tip 19.

In practice, if the tow is composed of ten 34-filament bulked yarns, thetow then is made up of 340 fine continuous filaments. After the tow iswound without tension about a stick or removable mandrel to the desiredswab or ball size, it is then cut, and because of the interlockingnature of the filaments, the swab or ball will hold together withoutunwinding. Because each of the 340 filaments in the swab is in acontinuous length running several feet, it cannot be separated from theother filaments and no lint exists.

Thus the advantage of the swab or other medical applicator made fromtexturized filaments of nylon or other synthetic material is the totalabsence of lint and other particles, coupled with the exceptionally highadsorbency of the tip. This makes it possible to use the swab in manydelicate medical and surgical procedures in which conventional swabs arenot acceptable. It will also be appreciated that it is possible to windthe tow into relatively large balls to provide lint-free sponges forlarge incisions and operations.

The nylon or other synthetic material used to form an applicator inaccordance with the invention is preferably of the type which includestitanium-oxide pigment or other radiologically opaque substances,whereby should the applicator be accidentally left behind in thepa-tients body, its rapid detection is made possible by X-raytechniques. In practice, the pigment is incorporated in the polymer meltprior to spinning, whereby the titanium oxide or other material isdispersed throughout the continuous filaments.

While there has been shown a preferred embodiment of lint-free swab inaccordance with the invention, it will be appreciated that many changesmay be made therein without departing from the essential spirit of theinvention as defined in the annexed claims.

What we claim is:

1. A lint-free medical device comprising a tow of texturized continuousmultifilament synthetic yarns wound into a mass having highly adsorbentproperties, the yarns forming said tow being individually false-twisted,the false-twisted yarns being intertangled in said tow.

2. A device, as set forth in claim 1, wherein said yarns incorporate aradiologically opaque pigmentary material' 3. A lint-free swabcomprising a stick and a mass of adsorbent material attached to one endof said stick, said material being constituted by a tow of yarns eachformed of continuous synthetic filaments, each yarn being individuallyfalse-twisted to enhance its adsorption properties, the false-twistedyarns being intertangled in said tow, said tow being wound about saidstick.

4. A swa'b as set forth in claim 3, wherein said filaments areconstituted by false-twisted nylon.

5. A swab as set forth in claim 3, wherein said filaments areconstituted by texturized polyamide filaments.

6. A swab as set forth in claim 3, wherein said filaments areconstituted by texturized polyvinyl filaments.

7. The method of forming a lint-free medical device, comprisingcontinuously texturizing a plurality of continuous multifilamentsynthetic yarns to form bulked yarns, said yarns being individuallyfalse-twisted, collecting said bulked yarns into a tow in inter-tangledrelationship to produce a matted mass, and winding said tow into a mass.

3. The method, as set forth in claim 7, wherein said tow is wound abouta stick.

9. The method, as set forth in claim 7, wherein said tow is wound abouta removable mandrel to form a ball.

10. The method, as set forth in claim 7, wherein said tow is wound intoa mass which is ensheathed within a fabric envelope to provide a shapeddressing.

References Cited UNITED STATES PATENTS 2,190,431 2/1940 Lewison 167-84 X2,987,063 6/1961 Glickston 128-269 3,177,872 4/1965 Pearman 128-263ADELE M. EAGER, Primary Examiner.

3. A LINT-FREE SWAB COMPRISING A STICK AND A MASS OF ADSORBENT MATERIALATTACHED TO ONE END OF SAID STICK, SAID MATERIAL BEING CONSTITUTED BY ATOW OF YARNS EACH FORMED OF CONTINUOUS SYNTHETIC FILAMENTS, EACH YARNBEING INDIVIDUALLY FALSE-TWISTED TO ENHANCE ITS ADSORPTION PROPERTIES,THE FALSE-TWISTED YARNS BEING INTERTANGLED IN SAID TOW, SAID TOW BEINGWOUND ABOUT SAID STICK.